<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

</body>
<script>
    var p = new Promise(function (resolve, reject) {
        aaaaaaaa;  // 报错 aaaaaaaa is not defined  Promise回调函数 在同步代码执行过程中 出现的错误
        // setTimeout(function () {
        // }, 2000)
    })
</script>

</html>